@Asifmd786
I would like to take a moment to thank you for posting on the HP Support Forums. I came across you post and would like to help. I understand that you have an HP Pavilion Notebook - 15-ab522tx and would like to add more memory and an 8GB graphics card.
I did some research and found the detailed hardware specifications for your laptop. This laptop has only 1 memory slot which is occupied by an 8GB memory card (8-GB (DDR3L-1600). HP has not tested this laptop to work with 16GB memory and hence I cannot make any speculations that the laptop motherboard will support 16GB memory.
Secondly, I did not could a slot on the motherboard which could accommodate an 8 GB graphics card. Therefore I would conclude that you may not be able to install a graphic card in it. Please refer to this user manual for detailed product specifications. Feel free to let me know if you have any questions. Cheers! 🙂